Author 
Topic 

Admin
Forum Admin
USA
635 Posts 
Posted  06/19/2012 : 21:45:18

What result do you get? I get 13, but my son insists it is 4.
166x22(53)
Thanks, Gisele 


royhaas
Moderator
USA
3059 Posts 
Posted  06/20/2012 : 09:50:03

16622(53)=16622(2)=16624=16124=163=13. 


Admin
Forum Admin
USA
635 Posts 
Posted  06/20/2012 : 10:17:05

quote: Originally posted by royhaas
16622(53)=16622(2)=16624=16124=163=13.
Thanks Roy. My thoughts exactly. This question will be included in an upcoming Flash game. 


Ultraglide
Advanced Member
Canada
299 Posts 
Posted  06/25/2012 : 12:40:35

Looking at part of the question, i.e. 6x22(2), this is the same as 6x22x2. Now if we follow the order of operations  multiplication and division in order from left to right this gives 12. So the final answer is 4. 


Admin
Forum Admin
USA
635 Posts 
Posted  06/25/2012 : 15:53:14

quote: Originally posted by Ultraglide
Looking at part of the question, i.e. 6x22(2), this is the same as 6x22x2. Now if we follow the order of operations  multiplication and division in order from left to right this gives 12. So the final answer is 4.
Thank you for your input, UltraGlide. I guess if us math folk can't agree on the solution, then this is not a good problem to hard code into a Flash game. I will post it on Facebook, though.
Gisele 


Ultraglide
Advanced Member
Canada
299 Posts 
Posted  06/25/2012 : 17:02:22

If you want to answer to come out to 13, just put parentheses around the 2(2) i.e. [2(2)]. 


the_hill1962
Advanced Member
USA
1469 Posts 
Posted  06/26/2012 : 15:54:23

I agree that the answer is 4. This is the reason why I have never liked the "Please Excuse My Dear Aunt Sally" (or PEMDAS) acronym. They do come to me knowing the acronym PEMDAS though so I suppose it served its purpose (having them remember the order). I tell them since multiplication and division are at the same level, so that PEMDAS is misleading if you forget that detail. This topic provides an example. I write on the board PEmdAS. I hook together the md and the AS (sort like they do in company logos hooking together letters).

Edited by  the_hill1962 on 09/13/2012 12:47:48 


royhaas
Moderator
USA
3059 Posts 
Posted  06/27/2012 : 11:32:08

If you faithfully follow the PEMDAS precedence rules, then the answer on almost any calculator is 4,
166*2/2*(53)=166*2/2*2=166*2/2*2=16(6*2/2*2)=1612=4.
Multiplication and division have the same precedence, so the (re)grouping is allowed. It seems that this is a common problem when both multiplication and division are concerned. That's why I trust my calculator more than my hand arithmetic.



Admin
Forum Admin
USA
635 Posts 
Posted  06/27/2012 : 11:38:58

Thanks everyone for your input!
Gisele 



Topic 
